1. FIELD OF THE INVENTION
The present invention relates to an apparatus for exposing the reinforcing bars of pillars made of reinforced concrete, which apparatus includes a supporting structure in the form of a frame of a box-type design having a central through passage for receipt of a pillar being handled and having a plurality of crushing tools located at the area of said central through passage and driven each by a piston-cylinder unit, which crushing tools are distributed along the entire circumference of said central through passage, and including a means for selectively feeding a pressurized fluid to each piston-cylinder unit.
2. DESCRIPTION OF THE PRIOR ART
The piston-cylinder units of a known apparatus for exposing the reinforcing bars of pillars made of reinforced concrete are arranged at a lying condition, i.e. in the working position of this known apparatus, these piston-cylinder units extend horizontally. Every such unit is thereby provided with a piston having a penetrating tip. A pressurized fluid is made to act upon the piston, thereby causing it to penetrate into a respective concrete pillar in order to break the concrete and to expose the reinforcing bars which is the object of such procedure. Correspondingly, the respective piston-cylinder units must be arranged or distributed such that the mentioned tips penetrate into a pillar to be handled at areas between the respective reinforcing bars, thereby to avoid damaging these bars. Because the distance between reinforcing bars depends individually on the cross-sectional dimensions of a concrete pillar, the respective distance between two tips of the pistons and correspondingly between the piston-cylinder units must be selected for each installation. This situation has now requires that a user must posess a relatively larger number of different such apparatuses which obviously renders the storing thereof rather expensive and thus causes high operating costs. Because the distances between reinforcing bars vary in accordance with the prevailing thickness of the concrete pillars as explained above, it is not possible to work on concrete pillars having rrther small dimensions by the application of as given apparatus which is actually designed for a larger pillar thickness because it is possible to move or adjust, respectively, rhe complete piston-cylinder unit sideways. Furthermore, the horizontally arranged design of the pistons such as explained above leads to such space requirements that it is not possible to operate with the known apparatus at concrete pillars having a small mutual spacing distance.
Due to mentioned horizontal arrangement of the piston-cylinder units, it also has not been possible to work on a concrete pillar at a level down to the respective ground level such that it was necessary either to dig further into the ground in order to expose the corresponding section of the concrete pillar or then to break the lowermost areas of the pillars off by a manual operating (for example, by means of a compressed air hammer).
In order to keep the lateral dimensions of the known apparatuses as small as possible it was absolutely necessary to operate with small piston-cylinder units such that the force exertable by these small units onto the respective pillars has been rather limited. Furthermore, the circuit of the pressurized fluid of these known apparatuses has been such that the pistons have been extended independently of each other such that it was not absolutely certain that the devices would center themselves around a concrete pillar such that the points, at which mentioned tips of the pistons penetrated into the pillars were not always located between the respective reinforcing bars which again has led to the danger of a damaging of these reinforcing bars.